Pistons



Dec. 22, 1959 J. KAPlTULA 2,918,337

PISTONS Filed July 16, 1957 FIG. 2 FIG I 4 1% FIGB 22 2O k Y1 k m INVENTOR.

36 Y JOHN KAPITULA United States Patent PISTONS John Kapitula, Jersey City, NJ.

Application July 16, 1957, Serial No. 672,182

4 Claims. (Cl. 309-4) This invention relates to pistons, as for internal combustion engines, jacks, hammers, etc., operated by the power of gas, steam, compressed air, or hydraulically, and has several advantages and numerous applications, as hereinafter pointed out and appreciated by those skilled in the art.

The drawings illustrate different forms of the invention, and in these Fig. l is a central longitudinal section of a piston Within a cylinder;

Fig. 2 is an end view of Fig. 1;

Fig. 3 is a central longitudinal section of a modified form of piston;

Fig. 4 is a cross section taken on line 4--4 of Fig. 3;

Fig. 5 is a central longitudinal section of another modification.

Referring to the drawings for a detailed description thereof, I show in Figs. 1 and 2, a cylinder containing a piston 11. The piston contains a symmetrical, central cavity extending inwardly from one end, said cavity comprising a funnel shaped end portion 12, which at its outer end has a diameter approximating that of the piston. This portion of the cavity serves to funnel the motive medium into a constricted portion 13, which functions as a venturi tube. Adjacent to, and inwardly of, the venturi, there is a section 14, substantially oval in longitudinal section, and beyond section 14 there is a constricted blind section 15. For practicability in forming the cavity described, the piston is made in 2 sections threadedly connected as shown at 16. The form of cavity described increases the area of pressure and therefore increases efiiciency, the venturi or constricted section 13 functioning to increase the velocity of the motive medium therethrough and building up pressure therebeyond, especially in the contricted end section 15, thus enabling a given pressure to be obtained with a smaller piston and diminishing the weight of the engine. This type of piston is useful for internal combustion engines, hydraulic pumps with either driving or driven pistons, hydraulic arbor presses, etc.

In Figs. 3 and 4, I show a cylinder 20, having a piston 21 slidable therein. The cylinder has a longiudtnal slot 21 to accommodate movement of an arm 22, which extends from the middle of the piston through the cylinder. This form of piston has similar cavities extending inwardly from each end, the cavities being of the same 6 form as that of Fig. 1. The cavities of Fig. 3 have parts numbered 24, 25, 26 and 27, corresponding respectively to the described parts 12, 13, 14 and 15 of the cavity in Fig. 1. As in piston 11 of Fig. 1, this piston 21 is in two sections threaded together at 28. This type of piston is useful, for example, in aircraft servo units, wherein the movement of a piston is hydraulically controlled and is connected to ailerons, rudders and elevators for automatic control of the plane. With the form of cavity described, there is obtained a greater pressure with a given size of piston. This piston is also useful in free piston engines by eliminating the arm 22 and the slot 21.

In Fig. 5, I show a cylinder 30, with a piston 31 therein. This piston has cavities extending from both ends, but they are of different form and develop different pressures. The cavity at the left is of the same form as shown in Figs. 1 and 3, and consists of parts 33, 34, 35 and 36, which correspond respectively to parts 12, 13, 14 and 15 of the cavity in Fig. 1. The cavity at the right end of the piston 31 is conical, as indicated at 38, with a constricted cylindrical portion 39 at the inner end thereof. The piston is in two parts threaded together at 40. This type of piston is useful in hydraulic or compressed gas systems. The two forms of cavity in this piston give a differential pressure, as desirable, for example, where two systems are to be operated from the same line but at different pressures, the pressure at the left end of the piston being greater than that at the right end.

What is claimed is:

1. A piston having a blind cavity in an end thereof, said cavity formed into a funnel-shaped portion adjacent to the end of the piston and having a constricted or venturi portion connecting with the funnel-shaped portion, and having, further, a third section adjacent to and connecting with the venturi section, said third section enlarging in diameter from the venturi section and then diminishing in diameter, and a fourth constricted section at the inner end of the third section.

2. The piston specified in claim 1, in which there is a cavity in the other end of the piston.

3. The piston specified in claim 1, in which there is a similar cavity in the other end of the piston.

4. The piston specified in claim 1, in which there is a conical cavity in the other end of the piston, with a constricted portion extending inwardly from the apex of said conical portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,759,160 Lang May 20, 1930 1,803,263 Lang Apr. 28, 1931 2,573,536 Bodine Oct. 30, 1951 2,662,510 French Dec. 15, 1953 FOREIGN PATENTS 351,633 Great Britain July 2, 1931 313,228 Switzerland Mar. 31, 1956 OTHER REFERENCES Benz: German application, Ser. No. 1,006,665, printed April 18, 1957 (K1 46a 79/01), 2 pp. spec. 1 sht. drg. 

